1. Field of the Invention
The present invention relates to the field of plant protection formulations. In particular, the invention relates to dispersions comprising herbicidal active substances which are known as hydroxyphenylpyruvate dioxygenase (HPPD) inhibitors.
2. Description of Related Art
Herbicidal active substances are conventionally not employed in their pure form. Depending on the field of application and the type of application, and on physical, chemical and biological parameters, the active substances are employed as active substance formulation as a mixture with customary adjuvants and additives. The combinations with further active substances for widening the spectrum of action and/or for protecting the crop plants (for example by safeners, antidotes) are also known.
In general, formulations of herbicidal active substances should have high chemical and physical stability, good application properties and user friendliness and a broad biological activity combined with high selectivity.
Hydroxyphenylpyruvate dioxygenase inhibitors are known as herbicides. Among these, benzobicyclon, isoxaflutole, mesotrione, pyrasulfotole, pyrazolynate, sulcotrione, tefuryltrione, tembotrione and topramezone are commercially available. Suspension concentrates or water-dispersible granules are already known as formulations of these active substances, see, for example, “The Pesticide Manual” 13th edition (2003), The British Crop Protection Council. EP 1 392 117 B1 discloses formulations of various hydroxyphenylpyruvate dioxygenase inhibitors in combination with certain fertilizers. WO 2008/135854-A2 discloses aqueous oil dispersions of 2-benzoyl-1,3-cyclohexanediones.
Depending on the intended use, the user demands formulations which are simple to handle and storage-stable. However, the formulations known from the prior art are not always satisfactory for these purposes.